2,676 research outputs found

    Independent AND-parallel implementation of narrowing

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    We present a parallel graph narrowing machine, which is used to implement a functional logic language on a shared memory multiprocessor. It is an extensión of an abstract machine for a purely functional language. The result is a programmed graph reduction machine which integrates the mechanisms of unification, backtracking, and independent and-parallelism. In the machine, the subexpressions of an expression can run in parallel. In the case of backtracking, the structure of an expression is used to avoid the reevaluation of subexpressions as far as possible. Deterministic computations are detected. Their results are maintained and need not be reevaluated after backtracking

    Grape musts differentiation based on selected aroma compounds using SBSE-GC-MS and statistical analysis

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    Fifty-one aroma compounds in musts from 'Muscat Ottonel', 'Aligoté', 'Muscat of Alexandria' and 'Pedro Ximénez' white grapes have been determined, three of them identified for the first time in grapes. Two fingerprints for each cultivar, based in 6 groups of aroma compounds before and after acidic hydrolysis of the musts were obtained by Multiple Variable Analysis. Only 17 aroma compounds before and 21 after hydrolysis, were selected by their high discriminating power. The Principal Component Analysis carried out with data of these selected compounds provided two components explaining 85.11 % of the overall variance for free aroma compounds and 87.58 % for those obtained after hydrolysis of musts, allowing an objective differentiation of each cultivar

    Regionalization and connectivity in the Gulf of Cádiz and Alborán Sea implication for marine spatial planning and coastal management

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    This work proposes a regionalization of marine waters south of the Iberian Peninsula based on empirical orthogonal functions and GIS analysis. The regions identified are consistent and correspond to hydrological mesoscale and macroscale structures well characterized from physical and biological viewpoints. Although it is difficult to determine the boundaries of a fluid continuously moving, the procedure used recognizes the most frequent patterns and can be used to reference geographically the most likely position of the limit among the regions. Once established the regions, the connectivity among them is addressed by means of geostrophic currents derived from altimetry data. The main geostrophic circulation pattern depict an elevate connectivity in the area that might facilitate the conservation and recovering of species, but also imply a higher vulnerability to negative externalities and highlight the need of models, marine spatial planning, and coastal management approaches that includes the pelagic ecosystem and connectivity of the seas. Furthermore, the results confirm that the cooperation between public authorities at different levels (local, regional, state) as well as among riparian countries is essential for marine spatial planning and prevention of potential risk derived from upcoming marine activities in the framework of the 2020 agenda and Blue Growth strategy.Universidad de Málaga. Campus de Excelencia Internacional Andalucía Tec

    Efficient implementation of general negation using abstract interpretation

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    While negation has been a very active área of research in logic programming, comparatively few papers have been devoted to implementation issues. Furthermore, the negation-related capabilities of current Prolog systems are limited. We recently presented a novel method for incorporating negation in a Prolog compiler which takes a number of existing methods (some modified and improved) and uses them in a combined fashion. The method makes use of information provided by a global analysis of the source code. Our previous work focused on the systematic description of the techniques and the reasoning about correctness and completeness of the method, but provided no experimental evidence to evalúate the proposal. In this paper, after proposing some extensions to the method, we provide experimental data which indicates that the method is not only feasible but also quite promising from the efficiency point of view. In addition, the tests have provided new insight as to how to improve the proposal further. Abstract interpretation techniques (in particular those included in the Ciao Prolog system preprocessor) have had a significant role in the success of the technique

    Molecular Physiology of Kainate Receptors

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    28 páginas, 15 figuras, 3 tablas.A decade ago, our understanding of the molecular properties of kainate receptors and their involvement in synaptic physiology was essentially null. A plethora of recent studies has altered this situation profoundly such that kainate receptors are now regarded as key players in the modulation of transmitter release, as important mediators of the postsynaptic actions of glutamate, and as possible targets for the development of antiepileptic and analgesic drugs. In this review, we summarize our current knowledge of the properties of kainate receptors focusing on four key issues:1) their structural and biophysical features, 2) the important progress in their pharmacological characterization,3) their pre- and postsynaptic mechanisms of action, and4) their involvement in a series of physiological and pathological processes. Finally, although significant progress has been made toward the elucidation of their importance for brain function, kainate receptors remain largely an enigma and, therefore, we propose some new roads that should be explored to obtain a deeper understanding of this young, but intriguing, class of proteins.Work in the laboratory of J. Lerma has been supported by grants from the Spanish Ministry of Education and Culture (DGICYT Grants PB93/0150 and UE96/0007 as well as DGESIC Grants PM-0008/96 and PM99–0106), the Ministry of Health (FISSS Grant 95/0869), the Comunidad de Madrid (Grant 08.5/ 0042/1998), and the European Union (Grant BIO2-CT930243). J. C. López-García is the recipient of a long-term fellowship awarded by EMBO.Peer reviewe

    Twisted flux tube emergence from the convection zone to the corona

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    3D numerical simulations of a horizontal magnetic flux tube emergence with different twist are carried out in a computational domain spanning the upper layers of the convection zone to the lower corona. We use the Oslo Staggered Code to solve the full MHD equations with non-grey and non-LTE radiative transfer and thermal conduction along the magnetic field lines. The emergence of the magnetic flux tube input at the bottom boundary into a weakly magnetized atmosphere is presented. The photospheric and chromospheric response is described with magnetograms, synthetic images and velocity field distributions. The emergence of a magnetic flux tube into such an atmosphere results in varied atmospheric responses. In the photosphere the granular size increases when the flux tube approaches from below. In the convective overshoot region some 200km above the photosphere adiabatic expansion produces cooling, darker regions with the structure of granulation cells. We also find collapsed granulation in the boundaries of the rising flux tube. Once the flux tube has crossed the photosphere, bright points related with concentrated magnetic field, vorticity, high vertical velocities and heating by compressed material are found at heights up to 500km above the photosphere. At greater heights in the magnetized chromosphere, the rising flux tube produces a cool, magnetized bubble that tends to expel the usual chromospheric oscillations. In addition the rising flux tube dramatically increases the chromospheric scale height, pushing the transition region and corona aside such that the chromosphere extends up to 6Mm above the photosphere. The emergence of magnetic flux tubes through the photosphere to the lower corona is a relatively slow process, taking of order 1 hour.Comment: 53 pages,79 figures, Submitted to Ap
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